In an article published in Nature, the BASE collaboration at CERN, Geneva, Switzerland, reports on the comparison of the antiproton-to-proton charge-to-mass ratio with eleven significant digits. This new measurement improves the precision of the previous best value by more than a factor of four, a considerable improvement in precision measurements. The data-set was accumulated over 1.5 years of measurement time, allowing for the first differential antiproton/proton test of the Einstein weak equivalence principle, which says that matter and antimatter behave the same under gravity.
Original publication:
M.J. Borchert et al., A 16-parts-per-trillion measurement of the antiproton-to-proton charge-mass ratio, Nature, 05.01.2022,
DOI: 10.1038/s41586-021-04203-w
www.nature.com/articles/s41586-021-04203-w